1949] Dinnik and Zumpt — Rhipicephalince 7 
shaped organs. He was unable to make ont all the de- 
tails of the terminal apparatus, but he presumed that 
they correspond in general to those of the sensilla sagit- 
tiformia and that a tuft-shaped structure is also present. 
The main difference lies, according to Schulze, in the 
upper portion of the passage leading to the outside. 
This lacks the long receding arrow-points, so that the 
“pagoda-shaped chamber,” formed by these points, is 
also missing. The passage is distinctly spear-shaped, in 
as much as it expands into two mainly horizontal pro- 
jections at the base. 
The larval sensillnm hastiforme could only be recog- 
nized as such after comparing it with the corresponding 
organ in nymphs and adults (Text-fig. 1, D-F). It lies 
as a short funnel-shaped structure in the lower part of 
the integument, which it pierces by means of a narrow 
passage, ending between the outer folds. The funnel- 
shaped portion is approximately 0.008 mm. in diameter 
and 0.005 mm. deep. The walls are about 0.002 mm. 
thick and the passage is roughly 0.008 mm. long. 
We were also unable to recognize the finer structure 
of the organ, nor could we find anything comparable to 
a “tuft.” In direct view the organ has the appearance 
of a ring, 0.008 mm. in diameter. Further details cannot 
be recognized, but by lowering the objective the duct 
leading inside the body may be followed. 
The larvae of Rhipicephalus appendiculatus Neum., Rh. 
sanguineus Latr., Rh. bursa Can. and Fanz., and Rh. 
evert si Nenm. studied by ns, all have 54 sensilla hasti- 
formia on the body proper; we did not examine the legs. 
The sensilla are placed strictly symmetrically and 
neither their position nor their number seem to vary to 
any extent (PI. 3, fig. 6). One pair is located on the 
capitnlnm, occupying the position taken by the areae 
porosae of the adult female tick. Five pairs are situated 
on the scutum and nine pairs on the alloscutum, four of 
these dorsal, one subdorsal and four sublateral. In addi- 
tion eight pairs are found on the edge of the alloscutum, 
one sensillum being placed on the edge of each festoon 
(or parmula), except on the middle festoon. The ar- 
